An interactive introduction to MATLAB

24 plotting

Exercise 3: Simple 2 d plotting

Please save all the plots you produce using the File → Save option in the Figure

Window. This should save a file with theMATLABdefault Figure format

which uses a .fig file extension.

1. Plot the following functions (you will need to decide on appropriate
   ranges forx):
   
   
   • y=^1 x, with a blue dashed line.
   
   
   • y=sin(x)cos(x), with a red dotted line.
   
   
   • y=2x^2 −3x+ 1 , with red cross markers.
     Turn thegrid onin all your plots, and remember to label axes and use
     a title.
   
   
   
   


2. Given the following function:

s=acos(φ) +

√

b^2 − (asin(φ) −c)^2

Plotsas a function of angleφwhena= 1 ,b= 1.5,c=0.3, and

06 φ 6360 ◦.

3. Plot the following parametric functions (you will need to use the
   axis equalcommand after yourplotcommand to forceMATLABto
   make the x-axis and y-axis the same length):
   a) A circle of radius 5 (revisit Ex2 Q7)
   b) Leminscate (−π/4 6 φ 6 π/4)

x=cos(φ)

√

2cos(2φ)

y=sin(φ)

√

2cos(2φ)

c) Logarithmic Spiral ( 06 φ 6 6π;k=0.1)

x=ekφcos(φ)

y=ekφsin(φ)

Exercise 3 Solutions

(http://www.eng.ed.ac.uk/teaching/courses/matlab/unit02/Ex3-

Solutions.shtml)